EPE type co-extrusion photovoltaic packaging adhesive film based on D-A dynamic cross-linking, preparation method and application of EPE type co-extrusion photovoltaic packaging adhesive film

Abstract

The invention belongs to the field of photovoltaic materials. The invention relates to an EPE type co-extrusion photovoltaic packaging adhesive film based on D-A dynamic crosslinking, which comprises three layers arranged in sequence, namely an EVA layer I, a POE layer and an EVA layer II, the thickness of the EVA layer I is 50 to 150 [mu] m; the thickness of the POE layer is 150 to 350 [mu] m; the thickness of the EVA layer II is 50-150 [mu] m, and dynamic D-A dynamic crosslinking occurs among the first EVA layer, the POE layer and the second EVA layer. Raw materials in the POE layer and the EVA layer respectively use a self-made functional aid I and a self-made functional aid II, the raw materials are blended according to a formula, the blended materials are injected into a double-screw extruder for three-layer co-extrusion, and film casting is performed to obtain the EPE type co-extrusion photovoltaic packaging adhesive film based on D-A dynamic crosslinking. The EPE type co-extrusion photovoltaic packaging adhesive film effectively solves the problems that in the prior art, auxiliaries migrate to an interface, so that layering between an EVA adhesive film layer and a POE adhesive film layer in the later period is caused, and the service life of materials is affected.

Description

Technical Field

[0001] The invention relates to an EPE type co-extruded photovoltaic encapsulation adhesive film based on DA dynamic cross-linking, a preparation method and application thereof. The invention belongs to the field of photovoltaic materials. Background Art

[0002] Photovoltaic encapsulation film is one of the key materials that affects the service life and power generation of photovoltaic modules. The technical research and development and upgrading of photovoltaic encapsulation film have a driving significance for the development of the photovoltaic industry. In addition to the two main encapsulation films of EVA and POE, a new type of composite film (EPE) has gradually developed in the industry. It is obtained by co-extruding EVA and POE, with POE as the middle layer and EVA as the outer layer on both sides, and the film product is obtained by compounding. This kind of film solves the adhesion defects of POE film and the PID effect problem of EVA film, and can reduce costs and increase efficiency to a certain extent. However, EPE film has the problem of POE layer additive migration (mainly cross-linking agent and silane coupling agent migration), which directly leads to the delamination of EVA and POE, affecting the service life of EPE film and seriously hindering the widespread application of EPE film.

[0003] There are currently two conventional methods to solve the delamination problem of EPE film. One is to make the additives macromolecular, mainly to modify the silane coupling agent into macromolecular form. Silane coupling agents are essential for the adhesion of film to glass, but they will also exist between the layers of EPE, which will cause stratification in severe cases. In addition, the macromolecular structure also has dispersion problems in the matrix, which in turn affects the material properties. The second is to solve the interface delamination problem of EVA and POE layers through compatibilizers, but there is currently no effective means to make the compatibilizer exist at the interface as much as possible and play a role. In addition, photovoltaics are used in harsh outdoor environments, and simple compatibility is difficult to maintain long-term interlayer bonding.

[0004] In view of the above factors, improving the interlayer bonding strength of EPE is currently the mainstream research direction of EPE, and will restrict the application potential of EPE co-extruded photovoltaic encapsulation film in the long term. Summary of the invention

[0005] The purpose of the present invention is to address the defects in the prior art that the polarity difference between POE and EVA in the EPE film is large, which causes the additives in POE to migrate to the interface, thereby causing the aging speed of the film to be too fast in the later stage, and the stratification problem between the EVA film layer and the POE film layer, thereby affecting the service life of the material. Based on the above problems, the present invention provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking and a preparation method thereof. Functional additives I and II are prepared by molecular design using DA dynamic cross-linking technology. After being added to the POE layer and the EVA layer respectively through formula design, they are prepared by three-layer co-extrusion technology, which can effectively solve the above problems and has a broad application space. The technical solution adopted by the present invention to solve its technical problems is: The present invention provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. The EPE encapsulation film comprises three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; the thickness of the first EVA layer is 50-150 μm; the thickness of the POE layer is 150-350 μm; the thickness of the second EVA layer is 50-150 μm; dynamic DA dynamic cross-linking occurs among the first EVA layer, the POE layer, and the second EVA layer.

[0006] The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; Cross-linking agent 0.5-1.5 parts; Auxiliary crosslinking agent I 0.5-1.0 part; Functional additive I 6.0-12.0 parts; Antioxidant 0.05-0.30 parts; Light stabilizer 0.05-0.30 parts.

[0007] The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; Cross-linking agent 0.5-1.0 part; Cross-linking agent II 0.1-0.5 part; Functional additive II 6.0-10.0 parts; Antioxidant 0.1-0.5 parts; Light stabilizer 0.1-0.5 parts.

[0008] The preparation method of the functional additive I comprises the following steps: S11, subjecting a furan dimethyl derivative containing a proton, a difunctional nucleophilic reagent, an aminosilane coupling agent and a diisocyanate to a nucleophilic addition reaction to obtain a target product, i.e., a functional additive I; The molar ratio of the proton-containing furan dimethyl derivative, the difunctional nucleophilic reagent, the aminosilane coupling agent and the diisocyanate is 0.55-0.85: 0.15-0.45: 0.10-0.20: 1.05.

[0009] The preparation method of the functional additive II comprises the following steps: S21, subjecting epoxyolefins and hydroxyolefins to free radical polymerization to obtain an intermediate product I; The molar ratio of the epoxy olefins to the hydroxy olefins is 0.60-0.80:0.20-0.40; S22, a proton-containing phenylmaleimide is subjected to a nucleophilic addition reaction with an asymmetric diisocyanate to obtain an intermediate II; The molar ratio of the proton-containing phenylmaleimide to the asymmetric diisocyanate is 1:1; S23, reacting the intermediate II with an asymmetric diamine to obtain the intermediate III; The molar ratio of the intermediate product II to the asymmetric diamine is 1:1; S24, subjecting the intermediate product I to a ring-opening reaction with the intermediate product III to obtain an intermediate product IV; The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; S25, hydrolyzing the intermediate product IV with a silane coupling agent to obtain a target product, i.e., a functional additive II; The usage ratio of the intermediate product IV to the silane coupling agent is 1:0.5-1.0 based on the molar ratio of hydroxyl group to silane coupling agent; and The hydroxyl group in the intermediate product IV is derived from hydroxyolefins.

[0010] Further, The furan dimethyl derivative containing a proton is 2,5-furan dimethanol or 2,5-furan dimethylamine; and The difunctional nucleophilic reagent is a diol or a diamine.

[0011] Further, The epoxy olefins are allyl epoxy structures or epoxy acrylate structures; and The hydroxyolefins are allyl hydroxyl structures or hydroxyacrylate structures.

[0012] Furthermore, the proton-containing phenylmaleimide is maleimidoaniline or 4-maleimidophenol.

[0013] Furthermore, the asymmetric diisocyanate is isophorone diisocyanate.

[0014] Furthermore, the asymmetric diamine is isophoronediamine.

[0015] Furthermore, the cross-linking agent is an organic peroxide.

[0016] Another object of the present invention is to provide a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, comprising the following steps: S31, mixing, i.e. The raw materials of each layer are mixed and configured according to the formula in a mixer to obtain mixed raw materials for standby use; S32, co-extrusion, i.e. The POE layer raw materials are placed in a twin-screw extruder for melt blending; the EVA layer raw materials are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched; S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

[0017] Furthermore, the POE layer extrusion process is as follows: barrel temperature 85-105°C, rotation speed 45-55rpm; and The EVA layer extrusion process is as follows: barrel temperature is 80-102° C. and rotation speed is 45-55 rpm.

[0018] Another object of the present invention is to provide an application of the above-mentioned EPE type co-extruded photovoltaic encapsulation film in the preparation of solar photovoltaic modules.

[0019] Beneficial effects of the present invention: (1) The present invention provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic crosslinking. The POE layer formula system contains a self-made functional additive I, which is a macromolecular chain containing a furan structure, a carbamate or urea structure in the main chain and terminated with a silane coupling agent. First, the furan structure can undergo a DA dynamic reaction with the phenylmaleimide in the functional additive II to enhance the interlayer bonding force; second, the silane structure helps to pull the macromolecular chain to migrate to the interface, so that it is enriched at the interface, further enhancing the interlayer bonding force; third, the macromolecular chain forms a chain entanglement with the POE matrix, synergistically enhancing the interlayer bonding force.

[0020] (2) The present invention provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic crosslinking, wherein the EVA formula system contains a self-made functional additive II, which is a macromolecule containing phenylmaleimide and silane structures in the side chain. First, phenylmaleimide can undergo DA dynamic reaction with the furan structure in the functional additive I to enhance the interlayer bonding force; and, it has a certain chain length in the side chain structure and is exposed to the outside, which can increase the contact probability with the main chain furan structure and improve the DA dynamic reaction effect; second, a large number of silane structures help to pull the macromolecular chain to migrate to the interface, so that it is enriched at the interface, further enhancing the interlayer bonding force; third, the fatty chain or ester structure in the main chain and the ester and amide structures in the side chain structure are conducive to its dispersibility in the EVA matrix; fourth, the macromolecular chain and the EVA matrix form chain entanglements to synergistically enhance the interlayer bonding force.

[0021] (3) The present invention provides a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. By using the co-extrusion technology, the EPE layer can be bonded in a softened state, thereby further improving the interlayer bonding strength and extending the service life. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to the examples. However, it should be understood that the following examples are only illustrative of the embodiments of the present invention, and are not intended to limit the scope of the present invention.

[0023] The purpose of the present invention is to develop an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking to meet the application requirements of existing photovoltaic encapsulation materials. The idea of ​​realization is: the current conventional use of small molecule additives for macromolecularization and the use of compatibilizers have certain problems. The present invention takes a different approach and adopts DA dynamic reaction cross-linking technology to design a chemical structure containing dynamic reactions in the EVA layer and the POE layer, which can ensure the existence of chemical reactions at the interface and improve the interlayer bonding force through chemical bonds, which has a better effect and can increase the ultimate service life of the EPE film. Specifically, functional additives I and II are designed, wherein functional additive I is a macromolecule containing a furan structure in the main chain; functional additive II is a macromolecule containing a maleimide structure in the side chain; when functional additives I and functional additives II are brought into contact with the interface, DA dynamic reaction cross-linking can be performed under certain temperature conditions; in order to further improve the dynamic reaction efficiency, both functional additives I and functional additives II are modified with a silane coupling agent to increase the interface enrichment degree, and in addition, the maleimide structure is placed at the side chain position and the side chain has a certain chain length to ensure that it is exposed to the outside to improve the DA dynamic reaction cross-linking effect. The theoretical basis for the realization is: for functional additive I, a proton-containing furan and a diamine (or diol) are subjected to a nucleophilic addition reaction with diisocyanate to form a macromolecular structure terminated with an isocyanate group, and the end-capping is prepared by an aminosilane coupling agent, which is functional additive I; for functional additive II, firstly, an olefin containing an epoxy group and a hydroxyl structure is subjected to free radical polymerization to obtain a macromolecular structure; then, a proton-containing maleimide structure is subjected to an affinity addition reaction with diisocyanate to prepare an isocyanate-terminated structure, and then an amino-terminated structure is prepared by an affinity addition reaction with a diamine, and next, a ring-opening reaction is carried out with a macromolecule containing an epoxy group to obtain a macromolecule containing maleimide in the side chain; finally, a silane hydrolysis reaction is carried out to prepare a macromolecule containing a silane structure in the side chain, which is functional additive II. The above functional additives I and II are added to the POE layer formula and the EVA layer formula system respectively, and three-layer co-extrusion is performed to prepare EPE adhesive film. The EPE film has high inter-layer bonding strength because the layers are bonded by chemical bonds. The embodiments of the present invention are as follows: The embodiment of the present invention provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. The EPE packaging film includes three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; The thickness of the first EVA layer is 50-150 μm; it can be 50 μm, 75 μm, 100 μm, 125 μm, 150 μm; or a range consisting of any two values; The thickness of the POE layer is 150-350 μm; it can be 150 μm, 200 μm, 250 μm, 300 μm; or a range consisting of any two values; The thickness of the second EVA layer is 50-150 μm; it can be 50 μm, 75 μm, 100 μm, 125 μm, 150 μm; or a range consisting of any two values; The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; Cross-linking agent 0.5-1.5 parts; Auxiliary crosslinking agent I 0.5-1.0 part; Functional additive I 6.0-12.0 parts; Antioxidant 0.05-0.30 parts; Light stabilizer 0.05-0.30 parts; The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; Cross-linking agent 0.5-1.0 part; Cross-linking agent II 0.1-0.5 part; Functional additive II 6.0-10.0 parts; Antioxidant 0.1-0.5 parts; Light stabilizer 0.1-0.5 parts; The preparation method of the functional additive I comprises the following steps: S11, subjecting a furan dimethyl derivative containing a proton, a difunctional nucleophilic reagent, an aminosilane coupling agent and a diisocyanate to a nucleophilic addition reaction to obtain a target product, i.e., a functional additive I; The furan dimethyl derivative containing a proton is 2,5-furan dimethanol or 2,5-furan dimethylamine; and The difunctional nucleophilic reagent is a diol or a diamine.

[0024] When the furan dimethyl derivative containing a proton is 2,5-furan dimethylamine; and the difunctional nucleophilic reagent is a diamine, S11 can be specifically S111, that is, S111, adding 2,5-furandimethylamine, diamine and diisocyanate to N,N-dimethylformamide, stirring at room temperature for 2-4 hours, adding aminosilane coupling agent, and continuing stirring for 1 hour; after the reaction is completed, vacuum distillation is performed, and vacuum drying is performed at 40° C. for 12 hours to obtain the target product, i.e., functional additive I; The usage ratio of the 2,5-furandimethylamine, diamine, aminosilane coupling agent, diisocyanate and N,N-dimethylformamide is 0.55-0.85 mol: 0.15-0.45 mol: 0.10-0.20 mol: 1.05 mol: 500 mL.

[0025] The diamine has a flexible structure and may be 1,4-butanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,3-propylenediamine, 2,2,4-trimethyl-1,6-hexanediamine, tetraethylenepentamine, triethylenetetramine, etc.; and 1,4-butanediamine is preferred.

[0026] The aminosilane coupling agent may be silane coupling agent KH901, silane coupling agent KH902, silane coupling agent KH540, silane coupling agent KH550, silane coupling agent KH602, or silane coupling agent KH792; and preferably, silane coupling agent KH550.

[0027] The diisocyanate may be TDI, MDI or HDI, etc., and MDI is preferred.

[0028] When the furan dimethyl derivative containing a proton is 2,5-furan dimethanol; and the difunctional nucleophilic reagent is a diol, S11 can be specifically S112, that is, S112, adding 2,5-furan dimethanol, diol, diisocyanate, and dibutyltin dilaurate to N,N-dimethylformamide, stirring, reacting at 40-70°C for 3-8h, cooling to room temperature, adding aminosilane coupling agent, and continuing stirring for 1h; after the reaction is completed, vacuum distillation is performed, and vacuum drying is performed at 40°C for 12h to obtain the target product, i.e., functional additive I; The usage ratio of 2,5-furan dimethanol, diol, aminosilane coupling agent, diisocyanate and N,N-dimethylformamide is 0.55-0.85 mol: 0.15-0.45 mol: 0.10-0.20 mol: 1.05 mol: 500 mL; The diol may be 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 2,2,4-trimethyl-1,6-hexanediol, diethylene glycol, etc., and preferably diethylene glycol.

[0029] The aminosilane coupling agent may be silane coupling agent KH901, silane coupling agent KH902, silane coupling agent KH540, silane coupling agent KH550, silane coupling agent KH602, or silane coupling agent KH792; and preferably, silane coupling agent KH550.

[0030] The diisocyanate may be TDI, MDI or HDI, etc., and MDI is preferred.

[0031] The amount of dibutyltin dilaurate used is 1.0wt% of the total mass of the reactants.

[0032] The functional additive I described in the present invention needs to take into account the migration of silane and the size of the molecular weight; if the molecular weight is too large, the occupancy rate of the silane coupling agent is too low, which will lead to a decrease in mobility, a low amount of the interface functional additive I, and a reduced effect of the dynamic crosslinking reaction, which will affect the interlayer bonding force; similarly, if the molecular weight is too small, the occupancy rate of the silane coupling agent is too high, which will lead to an increase in mobility, a high amount of the interface functional additive I, but the molecular weight is too small, resulting in insufficient chain entanglement with the matrix, which will ultimately affect the interlayer bonding force.

[0033] The preparation method of the functional additive II comprises the following steps: S21, pass N2, add epoxy olefins, hydroxy olefins and initiator AIBN into N,N-dimethylformamide, raise the temperature to 75-85°C, and stir for 6-10h; after the reaction is completed, cool to room temperature, filter, take the filtrate, distill under reduced pressure, and vacuum dry at 60°C for 6h to obtain intermediate product I.

[0034] The usage ratio of the epoxy olefins, hydroxy olefins and N,N-dimethylformamide is 0.60-0.80 mol: 0.20-0.40 mol: 500 mL.

[0035] The epoxy olefins are allyl epoxy structures or epoxy acrylate structures; The allyl epoxy structure may be allyl glycidyl ether, 1,2-epoxy-7-octene or 1,2-epoxy-9-decene, etc.; and preferably allyl glycidyl ether; The epoxy acrylate structure may be glycidyl methacrylate or (glycidyloxy)ethyl methacrylate, etc., and glycidyl methacrylate is preferred.

[0036] The hydroxy olefins are allyl hydroxyl structures or hydroxy acrylate structures; The allyl hydroxyl structure may be 4-penten-1-ol, 5-hexen-1-ol, 8-nonen-1-ol, 9-decen-1-ol, undecenol, etc.; and preferably 8-nonen-1-ol; The hydroxy acrylate structure may be hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, 4-hydroxybutyl acrylate, etc., and preferably hydroxyethyl methacrylate.

[0037] The amount of the initiator AIBN used is 1.5% of the total mass of the reactants.

[0038] S22, a proton-containing phenylmaleimide is subjected to a nucleophilic addition reaction with an asymmetric diisocyanate to obtain an intermediate II.

[0039] The molar ratio of the proton-containing phenylmaleimide to the asymmetric diisocyanate is 1:1; The proton-containing phenylmaleimide is maleimidoaniline or 4-maleimidophenol.

[0040] The asymmetric diisocyanate is isophorone diisocyanate.

[0041] When the proton-containing phenylmaleimide is maleimidoaniline, S22 may specifically be S221, that is, S221, maleimidoaniline and isophorone diisocyanate are added to N,N-dimethylformamide, and stirred at 35-45°C for 2-4 hours; the mixture is cooled to room temperature, distilled under reduced pressure, and dried under vacuum at 40°C for 8 hours to obtain intermediate II.

[0042] The dosage ratio of maleimidoaniline, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0043] When the proton-containing phenylmaleimide is 4-maleimidophenol, S22 may be specifically S222, that is, S222, add 4-maleimidophenol, isophorone diisocyanate, 2,6-di-tert-butyl-p-cresol and dibutyltin dilaurate to N,N-dimethylformamide, stir, react at 60-90°C for 4-8h, cool to room temperature, distill under reduced pressure, and vacuum dry at 40°C for 8h to obtain intermediate II.

[0044] The usage ratio of the 4-maleimidophenol, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0045] The amount of 2,6-di-tert-butyl-p-cresol used is 0.5 wt % of the mass of 4-maleimidophenol.

[0046] The amount of dibutyltin dilaurate used is 1.0wt% of the total mass of the reactants.

[0047] S23, adding the intermediate product II and isophorone diamine to N,N-dimethylformamide and stirring at room temperature for 2-4 hours; distilling under reduced pressure, and drying under vacuum at 40° C. for 8 hours to obtain the intermediate product III.

[0048] The usage ratio of the intermediate product II, isophoronediamine and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0049] S24, add intermediate product I, intermediate product III and triethylamine to N,N-dimethylformamide, stir at room temperature for 4-8 hours, add deionized water, shake, add ethyl acetate for extraction, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 40°C for 12 hours to obtain intermediate product IV.

[0050] The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; The usage ratio of the intermediate product III, triethylamine, N,N-dimethylformamide, deionized water, ethyl acetate, and anhydrous sodium sulfate is 0.1 mol: 0.01 mol: 200 mL: 250 mL: 600 mL: 5 g.

[0051] S25, adding the intermediate product IV and the silane coupling agent to an ethanol aqueous solution, adding acetic acid to adjust the pH value to 3.5-4.5, stirring at 40-60°C for 2-4 hours, distilling under reduced pressure, and vacuum drying at 60°C for 8 hours to obtain the target product, i.e., functional additive II.

[0052] The usage ratio of the intermediate product IV and the ethanol aqueous solution is 0.1 mol:500 mL; The usage ratio of the intermediate product IV to the silane coupling agent is 1:0.5-1.0 based on the molar ratio of hydroxyl group to silane coupling agent; and the hydroxyl group in the intermediate product IV comes from hydroxy olefins.

[0053] The ethanol aqueous solution has an ethanol content of 95 wt %.

[0054] The silane coupling agent may be an aminosilane coupling agent or a vinylsilane coupling agent, etc.; and preferably a vinylsilane coupling agent, more specifically silane coupling agent KH171.

[0055] The functional additive II in the present invention is a side group containing a certain chain length of N-phenyl maleimide, and is located in the side group structure, can be freely extended, and is easy to react with furan for dynamic crosslinking to improve the interlayer bonding strength. In addition, similar to the functional additive I, there is also the influence of silane migration and molecular weight on the interlayer bonding strength.

[0056] The functional additives I and II described in the present invention can undergo a DA dynamic reaction and are thermally reversible. The DA reaction occurs above 60°C, which is a heat-induced [4+2] cycloaddition reaction between the diene on the furan group and the imine group dienophile in N-phenylmaleimide, i.e., a cross-linked structure is formed; when the temperature rises to about 130°C, a DA reverse reaction occurs to generate a diene and a dienophile structure, i.e., a decrosslinking reaction; when the temperature decreases, a DA reaction occurs, and a DA adduct is formed again, which is a heat-induced dynamic cross-linking reaction. This dynamic thermal reaction interval can be compatible with photovoltaic lamination and subsequent use, i.e., a DA reverse reaction occurs during lamination, which helps to complete the fusion between layers and release internal stress; after the lamination is completed, a DA reaction occurs to form a cross-link, and the cross-linked structure can be maintained during subsequent use, thereby improving the interfacial bonding strength and actually forming the integration of EVA and POE to avoid delamination and performance failure.

[0057] The octene content in the POE resin described in the present invention is 20-35wt%; it can be 20wt%, 25wt%, 30wt%, 35wt% or a range consisting of any two values; and the octene content in the POE resin described in the following embodiments of the present invention is 25wt%.

[0058] The crosslinking agent in the present invention is an organic peroxide; specifically, it can be tert-butyl peroxide 2-ethylhexyl carbonate, dibenzoyl peroxide, 2,5-dimethyl-2,5-bis(benzoylperoxide)hexane or 1,1-(tert-butyl peroxide)-3,3,5-trimethylcyclohexane, etc.; and the crosslinking agent in the following embodiments of the present invention is dibenzoyl peroxide.

[0059] The auxiliary crosslinking agent I in the present invention is one or more of trimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, triallyl isocyanurate, and triallyl cyanurate; and, in the following embodiments of the present invention, the auxiliary crosslinking agent I is triallyl isocyanurate.

[0060] The EVA resin described in the present invention has a VA content of 33% and a melt index (MI) of 31, and is purchased from DuPont Company of the United States.

[0061] The auxiliary crosslinking agent II in the present invention is one or more of trimethylolpropane trimethacrylate, ethoxylated pentaerythritol tetraacrylate, ethoxylated trimethylolpropane triacrylate, propoxylated neopentyl glycol diacrylate, pentaerythritol triacrylate, triallyl isocyanurate, and triallyl cyanurate; and, in the following embodiments of the present invention, the auxiliary crosslinking agent II is ethoxylated trimethylolpropane triacrylate and triallyl isocyanurate added in a mass ratio of 1:3.

[0062] The antioxidant described in the present invention is a mixture of a hindered phenol antioxidant and a phosphite antioxidant; The hindered phenol antioxidant can be antioxidant 1010, antioxidant 1076, antioxidant 264, antioxidant 2246, etc., and antioxidant 1010 is preferred; the phosphite antioxidant can be antioxidant 168, antioxidant 242, antioxidant TPP, etc., and antioxidant 168 is preferred; the antioxidant described in the following embodiments of the present invention is antioxidant 1010 and antioxidant 168 added in a mass ratio of 1:2.

[0063] The light stabilizer in the present invention is a mixture of a hindered amine light stabilizer and an ultraviolet absorber; The hindered amine light stabilizer can be UV-292, UV-770 or GW540, etc., and UV-292 is preferred; the ultraviolet absorber can be UV-326, UV-327 or UV-531, etc., and UV-531 is preferred; the light stabilizer described in the following embodiments of the present invention is UV-292 and UV-531 added in a mass ratio of 1:2.

[0064] Another object of the embodiment of the present invention is to provide a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, comprising the following steps: S31, mixing, i.e. The raw materials of each layer were mixed and configured according to the formula in a mixer, and mixed and stirred at a temperature of 40° C. and a speed of 80 rpm for 2 h to obtain a mixed raw material for standby use; S32, co-extrusion, i.e. The POE layer raw materials are placed in a twin-screw extruder for melt blending; the EVA layer raw materials are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched; The POE layer extrusion process is as follows: barrel temperature 85-105°C, rotation speed 45-55rpm; and The EVA layer extrusion process is as follows: barrel temperature is 80-102° C. and rotation speed is 45-55 rpm.

[0065] S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

[0066] Another object of the embodiments of the present invention is to provide an application of the above-mentioned EPE type co-extruded photovoltaic encapsulation film in the preparation of solar photovoltaic modules.

[0067] In order to further understand the present invention, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking provided by the present invention is described in detail below in conjunction with specific embodiments, and the protection scope of the present invention is not limited by the following embodiments.

[0068] Example 1 This embodiment provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. The EPE packaging film includes three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; The thickness of the first EVA layer is 100 μm; The thickness of the POE layer is 250 μm; The thickness of the second EVA layer is 100 μm; The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; 1.0 part of cross-linking agent; 0.8 part of co-crosslinking agent 1; Functional additive I 9.0 parts; Antioxidant 0.20 parts; Light stabilizer 0.10 parts; The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; 0.8 part of cross-linking agent; 0.35 part of auxiliary crosslinking agent II; Functional additive II 8.0 parts; 0.3 parts of antioxidant; Light stabilizer 0.4 parts; The preparation method of the functional additive I comprises the following steps: S11 (i.e. S111), 2,5-furandimethylamine, 1,4-butanediamine, and MDI were added to N,N-dimethylformamide, stirred at room temperature for 3 hours, and then silane coupling agent KH550 was added, and stirring was continued for 1 hour. After the reaction was completed, the mixture was distilled under reduced pressure and dried in a vacuum at 40°C for 12 hours to obtain the target product, i.e. functional additive I ( ); The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.70 mol: 0.30 mol: 0.15 mol: 1.05 mol: 500 mL.

[0069] Its infrared data are as follows: 3320 cm -1 :-NH- peak exists and weakens; 3011cm-1 、1595cm -1 、1480cm -1 : benzene ring exists; 2270 cm -1 :-NCO does not exist; 1674 cm -1 :-C=O exists; 1613cm -1 :-C=C- exists; 1551 cm -1 :Amide-NH- exists; 1109 cm -1 、797cm -1 :-Si-O- exists.

[0070] The preparation method of the functional additive II comprises the following steps: S21, pass N2, add glycidyl methacrylate, hydroxyethyl methacrylate and initiator AIBN into N,N-dimethylformamide A, heat to 80°C, and stir for 7.5h. After the reaction, cool to room temperature, filter, take the filtrate, distill under reduced pressure, and vacuum dry at 60°C for 6h to obtain intermediate I ( ).

[0071] The usage ratio of glycidyl methacrylate, hydroxyethyl methacrylate and N,N-dimethylformamide A is 0.70 mol: 0.30 mol: 500 mL.

[0072] The amount of the initiator AIBN used is 1.5% of the total mass of the reactants.

[0073] Its infrared data is as follows: 3457cm -1 :-OH exists; 1735 cm -1 :-C=O exists; 1605 cm -1 , 811 cm -1 :-C=C- does not exist; 1263cm -1 、895cm -1 、827cm -1 : Epoxy group exists.

[0074] S22 (i.e., S221), maleimidoaniline and isophorone diisocyanate are added to N,N-dimethylformamide, and stirred at 40°C for 2.5 hours; the mixture is cooled to room temperature, distilled under reduced pressure, and dried in a vacuum at 40°C for 8 hours to obtain intermediate II.

[0075] The dosage ratio of maleimidoaniline, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0076] Its infrared data are as follows: 3318 cm -1: -NH- peak exists and weakens; 3021cm -1 、1582cm -1 、1480cm -1 : benzene ring exists; 2270 cm -1 :-NCO exists and weakens; 1656 cm -1 、1668 cm -1 :-C=O exists; 1623 cm -1 :-C=C- exists; 1551 cm -1 : Amide -NH- exists.

[0077] S23, the intermediate product II and isophorone diamine are added to N,N-dimethylformamide and stirred at room temperature for 3 hours; the mixture is distilled under reduced pressure and dried in a vacuum at 40° C. for 8 hours to obtain the intermediate product III.

[0078] The usage ratio of the intermediate product II, isophoronediamine and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0079] Its infrared data are as follows: 3319 cm -1 : -NH- peak exists and is enhanced; 3021cm -1 、1582cm -1 、1480cm -1 : benzene ring exists; 2270 cm -1 :-NCO does not exist; 1656 cm -1 、1668 cm -1 :-C=O exists and is enhanced; 1623 cm -1 :-C=C- exists; 1551 cm -1 : Amide -NH- exists and is enhanced.

[0080] S24, add intermediate product I, intermediate product III and triethylamine to N,N-dimethylformamide, stir at room temperature for 6.5 hours, add deionized water, shake, add ethyl acetate for extraction, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 40°C for 12 hours to obtain intermediate product IV.

[0081] The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; The usage ratio of the intermediate product III, triethylamine, N,N-dimethylformamide, deionized water, ethyl acetate, and anhydrous sodium sulfate is 0.1 mol: 0.01 mol: 200 mL: 250 mL: 600 mL: 5 g.

[0082] Its infrared data are as follows: 3456cm-1 :-OH exists and enhances; 3318 cm -1 : -NH- peak exists and weakens; 3021cm -1 、1582cm -1 、1480cm -1 : benzene ring exists; 1735 cm -1 :Ester-C=O exists; 1656 cm -1 、1668 cm -1 :Amide-C=O exists; 1623 cm -1 :-C=C- exists; 1551 cm -1 :Amide-NH- exists; 1263cm -1 、895cm -1 、827cm -1 : Epoxy group does not exist.

[0083] S25, adding the intermediate product IV and the silane coupling agent KH171 to an ethanol aqueous solution, adding acetic acid to adjust the pH value to 4.0, stirring at 50°C for 3 hours, distilling under reduced pressure, and vacuum drying at 60°C for 8 hours to obtain the target product, i.e., functional additive II.

[0084] The usage ratio of the intermediate product IV and the ethanol aqueous solution is 0.1 mol:500 mL; The usage ratio of the intermediate product IV and the silane coupling agent KH171 is 1:0.7 in terms of the molar ratio of hydroxyl group to silane coupling agent; and the hydroxyl group in the intermediate product IV comes from hydroxy olefins.

[0085] The ethanol aqueous solution has an ethanol content of 95 wt %.

[0086] Its infrared data are as follows: 3454cm -1 :-OH exists and weakens; 3318 cm -1 : -NH- sharp peak exists; 3021cm -1 、1582cm -1 、1480cm -1 : benzene ring exists; 1735 cm -1 :Ester-C=O exists; 1656 cm -1 、1668 cm -1 :Amide-C=O exists; 1623 cm -1 :Maleimide-C=C-exists; 1600 cm -1 :Silane-C=C- exists; 1551 cm -1 :Amide-NH- exists; 1103 cm -1 、792cm -1 :-Si-O- exists.

[0087] Another object of this embodiment is to provide a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, comprising the following steps: S31, mixing, i.e. The raw materials of each layer were mixed and configured according to the formula in a mixer, and mixed and stirred for 2 hours at a temperature of 40° C. and a rotation speed of 80 rpm to obtain a mixed raw material for standby use.

[0088] S32, co-extrusion, i.e. The raw materials of the POE layer are placed in a twin-screw extruder for melt blending; the raw materials of the EVA layer are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched.

[0089] The POE layer extrusion process is as follows: the temperature of the barrel zone 1 is 90°C, the temperature of the zone 2 is 98°C, the temperature of the zone 3 is 105°C, the die temperature is 105°C, and the rotation speed is 50rpm; and The EVA layer extrusion process is as follows: the temperature of the barrel zone 1 is 85° C., the temperature of the barrel zone 2 is 94° C., the temperature of the barrel zone 3 is 100° C., the die head temperature is 100° C., and the rotation speed is 50 rpm.

[0090] S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

[0091] Another purpose of this embodiment is to provide an application of the above-mentioned EPE type co-extruded photovoltaic encapsulation film in the preparation of solar photovoltaic modules.

[0092] Example 2 This embodiment provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. The EPE packaging film includes three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; The thickness of the first EVA layer is 150 μm; The thickness of the POE layer is 150 μm; The thickness of the second EVA layer is 150 μm; The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; 0.5 part of cross-linking agent; 1.0 part of co-crosslinking agent I; Functional additive I 6.0 parts; Antioxidant 0.05 parts; Light stabilizer 0.30 parts; The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; 1.0 part of cross-linking agent; 0.1 part of auxiliary crosslinking agent II; Functional additive II 10.0 parts; 0.5 parts of antioxidant; Light stabilizer 0.1 part; The preparation method of the functional additive I comprises the following steps: S11 (i.e. S111), 2,5-furandimethylamine, 1,4-butanediamine, and MDI were added to N,N-dimethylformamide, stirred at room temperature for 2 hours, and then silane coupling agent KH550 was added, and stirring was continued for 1 hour. After the reaction was completed, the mixture was distilled under reduced pressure and dried in a vacuum at 40°C for 12 hours to obtain the target product, i.e. functional additive I ( ); The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.85 mol: 0.15 mol: 0.20 mol: 1.05 mol: 500 mL.

[0093] The preparation method of the functional additive II comprises the following steps: S21, pass N2, add glycidyl methacrylate, hydroxyethyl methacrylate and initiator AIBN into N,N-dimethylformamide A, heat to 75°C, and stir for 10h. After the reaction, cool to room temperature, filter, take the filtrate, distill under reduced pressure, and vacuum dry at 60°C for 6h to obtain intermediate I ( ).

[0094] The usage ratio of glycidyl methacrylate, hydroxyethyl methacrylate and N,N-dimethylformamide A is 0.60 mol: 0.40 mol: 500 mL.

[0095] The amount of the initiator AIBN used is 1.5% of the total mass of the reactants.

[0096] S22 (i.e., S221), maleimidoaniline and isophorone diisocyanate are added to N,N-dimethylformamide, and stirred at 35°C for 4 hours; the mixture is cooled to room temperature, distilled under reduced pressure, and dried in a vacuum at 40°C for 8 hours to obtain intermediate product II.

[0097] The dosage ratio of maleimidoaniline, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0098] S23, the intermediate product II and isophorone diamine are added to N,N-dimethylformamide and stirred at room temperature for 2 hours; the mixture is distilled under reduced pressure and dried in a vacuum at 40° C. for 8 hours to obtain the intermediate product III.

[0099] The usage ratio of the intermediate product II, isophoronediamine and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0100] S24, add intermediate product I, intermediate product III and triethylamine to N,N-dimethylformamide, stir at room temperature for 4 hours, add deionized water, shake, add ethyl acetate for extraction, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 40°C for 12 hours to obtain intermediate product IV.

[0101] The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; The usage ratio of the intermediate product III, triethylamine, N,N-dimethylformamide, deionized water, ethyl acetate, and anhydrous sodium sulfate is 0.1 mol: 0.01 mol: 200 mL: 250 mL: 600 mL: 5 g.

[0102] S25, adding the intermediate product IV and the silane coupling agent KH171 to an ethanol aqueous solution, adding acetic acid to adjust the pH value to 3.5, stirring at 60°C for 2 hours, distilling under reduced pressure, and vacuum drying at 60°C for 8 hours to obtain the target product, i.e., functional additive II.

[0103] The usage ratio of the intermediate product IV and the ethanol aqueous solution is 0.1 mol:500 mL; The usage ratio of the intermediate product IV and the silane coupling agent KH171 is 1:0.5 based on the molar ratio of hydroxyl group to silane coupling agent; and the hydroxyl group in the intermediate product IV comes from hydroxy olefins.

[0104] The ethanol aqueous solution has an ethanol content of 95 wt %.

[0105] Another object of this embodiment is to provide a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, comprising the following steps: S31, mixing, i.e. The raw materials of each layer were mixed and configured according to the formula in a mixer, and mixed and stirred for 2 hours at a temperature of 40° C. and a rotation speed of 80 rpm to obtain a mixed raw material for standby use.

[0106] S32, co-extrusion, i.e. The raw materials of the POE layer are placed in a twin-screw extruder for melt blending; the raw materials of the EVA layer are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched.

[0107] The POE layer extrusion process is as follows: the temperature of the barrel zone 1 is 95°C, the temperature of the zone 2 is 100°C, the temperature of the zone 3 is 105°C, the die head temperature is 105°C, and the rotation speed is 45 rpm; and The EVA layer extrusion process is as follows: the temperature of the barrel zone 1 is 90° C., the temperature of the barrel zone 2 is 97° C., the temperature of the barrel zone 3 is 102° C., the die head temperature is 102° C., and the rotation speed is 45 rpm.

[0108] S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

[0109] Another purpose of this embodiment is to provide an application of the above-mentioned EPE type co-extruded photovoltaic encapsulation film in the preparation of solar photovoltaic modules.

[0110] Example 3 This embodiment provides an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking. The EPE packaging film includes three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; The thickness of the first EVA layer is 50 μm; The thickness of the POE layer is 350 μm; The thickness of the second EVA layer is 50 μm; The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; 1.5 parts of cross-linking agent; 0.5 part of co-crosslinking agent; Functional additive I 12.0 parts; Antioxidant 0.30 parts; Light stabilizer 0.05 parts; The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; 0.5 part of cross-linking agent; 0.5 part of auxiliary crosslinking agent II; Functional additive II 6.0 parts; Antioxidant 0.1 part; 0.5 parts of light stabilizer; The preparation method of the functional additive I comprises the following steps: S11 (i.e. S111), 2,5-furandimethylamine, 1,4-butanediamine, and MDI were added to N,N-dimethylformamide, stirred at room temperature for 4 hours, and then silane coupling agent KH550 was added, and stirring was continued for 1 hour. After the reaction was completed, the mixture was distilled under reduced pressure and dried in a vacuum at 40°C for 12 hours to obtain the target product, i.e. functional additive I ( ); The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.55 mol: 0.45 mol: 0.10 mol: 1.05 mol: 500 mL.

[0111] The preparation method of the functional additive II comprises the following steps: S21, pass N2, add glycidyl methacrylate, hydroxyethyl methacrylate and initiator AIBN into N,N-dimethylformamide A, heat to 85°C, and stir for 6h. After the reaction, cool to room temperature, filter, take the filtrate, distill under reduced pressure, and vacuum dry at 60°C for 6h to obtain intermediate I ( ).

[0112] The usage ratio of glycidyl methacrylate, hydroxyethyl methacrylate and N,N-dimethylformamide A is 0.80 mol: 0.20 mol: 500 mL.

[0113] The amount of the initiator AIBN used is 1.5% of the total mass of the reactants.

[0114] S22 (i.e., S221), maleimidoaniline and isophorone diisocyanate are added to N,N-dimethylformamide, and stirred at 45°C for 2 hours; the mixture is cooled to room temperature, distilled under reduced pressure, and dried in a vacuum at 40°C for 8 hours to obtain intermediate product II.

[0115] The dosage ratio of maleimidoaniline, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0116] S23, the intermediate product II and isophorone diamine are added to N,N-dimethylformamide and stirred at room temperature for 4 hours; the mixture is distilled under reduced pressure and dried in a vacuum at 40° C. for 8 hours to obtain the intermediate product III.

[0117] The usage ratio of the intermediate product II, isophoronediamine and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0118] S24, add intermediate product I, intermediate product III and triethylamine to N,N-dimethylformamide, stir at room temperature for 8 hours, add deionized water, shake, add ethyl acetate for extraction, take the organic phase, dry it with anhydrous sodium sulfate, filter, take the filtrate, distill it under reduced pressure, and dry it in vacuo at 40°C for 12 hours to obtain intermediate product IV.

[0119] The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; The usage ratio of the intermediate product III, triethylamine, N,N-dimethylformamide, deionized water, ethyl acetate, and anhydrous sodium sulfate is 0.1 mol: 0.01 mol: 200 mL: 250 mL: 600 mL: 5 g.

[0120] S25, adding the intermediate product IV and the silane coupling agent KH171 to an ethanol aqueous solution, adding acetic acid to adjust the pH value to 4.5, stirring at 40°C for 4 hours, distilling under reduced pressure, and vacuum drying at 60°C for 8 hours to obtain the target product, i.e., functional additive II.

[0121] The usage ratio of the intermediate product IV and the ethanol aqueous solution is 0.1 mol:500 mL; The usage ratio of the intermediate product IV and the silane coupling agent KH171 is 1:1.0 based on the molar ratio of hydroxyl group to silane coupling agent; and the hydroxyl group in the intermediate product IV comes from hydroxy olefins.

[0122] The ethanol aqueous solution has an ethanol content of 95 wt %.

[0123] Another object of this embodiment is to provide a method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, comprising the following steps: S31, mixing, i.e. The raw materials of each layer were mixed and configured according to the formula in a mixer, and mixed and stirred for 2 hours at a temperature of 40° C. and a rotation speed of 80 rpm to obtain a mixed raw material for standby use.

[0124] S32, co-extrusion, i.e. The raw materials of the POE layer are placed in a twin-screw extruder for melt blending; the raw materials of the EVA layer are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched.

[0125] The POE layer extrusion process is as follows: the temperature of the barrel zone 1 is 85°C, the temperature of the barrel zone 2 is 94°C, the temperature of the barrel zone 3 is 100°C, the die head temperature is 100°C, and the rotation speed is 55 rpm; and The EVA layer extrusion process is as follows: the temperature of the barrel zone 1 is 80° C., the temperature of the barrel zone 2 is 90° C., the temperature of the barrel zone 3 is 98° C., the die head temperature is 98° C., and the rotation speed is 55 rpm.

[0126] S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

[0127] Another purpose of this embodiment is to provide an application of the above-mentioned EPE type co-extruded photovoltaic encapsulation film in the preparation of solar photovoltaic modules.

[0128] Example 4 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; 1.0 part of cross-linking agent; 0.8 part of co-crosslinking agent 1; Functional additive I 7.0 parts; Antioxidant 0.20 parts; Light stabilizer 0.10 parts

[0129] Example 5 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The POE layer comprises the following raw materials in parts by weight: POE resin 100 parts; 1.0 part of cross-linking agent; 0.8 part of co-crosslinking agent 1; Functional additive I 11.0 parts; Antioxidant 0.20 parts; Light stabilizer 0.10 parts

[0130] Example 6 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; 0.8 part of cross-linking agent; 0.35 part of auxiliary crosslinking agent II; Functional additive II 7.0 parts; 0.3 parts of antioxidant; Light stabilizer 0.4 parts

[0131] Example 7 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; 0.8 part of cross-linking agent; 0.35 part of auxiliary crosslinking agent II; Functional additive II 9.0 parts; 0.3 parts of antioxidant; Light stabilizer 0.4 parts

[0132] Example 8 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.80 mol: 0.20 mol: 0.15 mol: 1.05 mol: 500 mL.

[0133] Example 9 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.60 mol: 0.40 mol: 0.15 mol: 1.05 mol: 500 mL.

[0134] Example 10 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, step S11 is S112, namely: S11 (i.e., S112), adding 2,5-furan dimethanol, diethylene glycol, MDI, and dibutyltin dilaurate to N,N-dimethylformamide, stirring, reacting at 60°C for 5 hours, cooling to room temperature, adding silane coupling agent KH550, and continuing stirring for 1 hour; after the reaction is completed, vacuum distillation is performed, and vacuum drying is performed at 40°C for 12 hours to obtain the target product, i.e., functional additive I; The usage ratio of 2,5-furan dimethanol, diethylene glycol, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.70 mol: 0.30 mol: 0.15 mol: 1.05 mol: 500 mL; The amount of dibutyltin dilaurate used is 1.0wt% of the total mass of the reactants.

[0135] Its infrared data are as follows: 3436 cm -1 :-OH does not exist; 3011cm -1 、1595cm -1 、1480cm -1 : benzene ring exists; 2270 cm -1 :-NCO does not exist; 1715 cm -1 :-C=O exists; 1613cm -1 :-C=C- exists; 1551 cm -1 :Amide-NH- exists; 1109 cm -1 、797cm -1 :-Si-O- exists.

[0136] Embodiment 11 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive II, in S21, The usage ratio of glycidyl methacrylate, hydroxyethyl methacrylate and N,N-dimethylformamide A is 0.60 mol: 0.40 mol: 500 mL.

[0137] Example 12 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive II, in S21, The usage ratio of glycidyl methacrylate, hydroxyethyl methacrylate and N,N-dimethylformamide A is 0.80 mol: 0.20 mol: 500 mL.

[0138] Embodiment 13 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The glycidyl methacrylate was replaced with allyl glycidyl ether.

[0139] Embodiment 14 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The hydroxyethyl methacrylate was replaced by 8-nonen-1-ol.

[0140] Embodiment 15 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The glycidyl methacrylate and hydroxyethyl methacrylate are replaced by allyl glycidyl ether and 8-nonen-1-ol, respectively.

[0141] Example 16 The rest is the same as in Example 1, except that: In this embodiment, the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive II, step S22 is S222, namely: S22 (i.e., S222), add 4-maleimidophenol, isophorone diisocyanate, 2,6-di-tert-butyl-p-cresol, and dibutyltin dilaurate to N,N-dimethylformamide, stir, react at 75°C for 7 hours, cool to room temperature, distill under reduced pressure, and vacuum dry at 40°C for 8 hours to obtain intermediate product II.

[0142] The usage ratio of the 4-maleimidophenol, isophorone diisocyanate and N,N-dimethylformamide is 1 mol: 1 mol: 500 mL.

[0143] The amount of 2,6-di-tert-butyl-p-cresol used is 0.5 wt % of the mass of 4-maleimidophenol.

[0144] The amount of dibutyltin dilaurate used is 1.0wt% of the total mass of the reactants.

[0145] Its infrared data are as follows: 3429 cm -1 :-OH does not exist; 3021cm -1 、1582cm -1 、1480cm -1 : benzene ring exists; 2270 cm -1:-NCO exists and weakens; 1711 cm -1 :-C=O exists; 1656 cm -1 :-C=O exists; 1623 cm -1 :-C=C-exists.

[0146] The EPE type co-extruded photovoltaic encapsulation films in the following comparative examples are compared with Example 1: Comparative Example 1 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, In the POE layer formula, no functional additive I is added.

[0147] Comparative Example 2 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, In the EVA layer formula, no functional additive II is added.

[0148] Comparative Example 3 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The 2,5-furandimethylamine was replaced with tetrahydro-2,5-furandimethylamine.

[0149] Comparative Example 4 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The silane coupling agent KH550 was replaced with 5-methylglucosamine.

[0150] Comparative Example 5 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.70 mol: 0.30 mol: 0.075 mol: 1.025 mol: 500 mL.

[0151] Comparative Example 6 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive I, in S11, The usage ratio of the 2,5-furandimethylamine, 1,4-butanediamine, silane coupling agent KH550, MDI, and N,N-dimethylformamide is 0.70 mol: 0.30 mol: 0.30 mol: 1.1 mol: 500 mL.

[0152] Comparative Example 7 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive II, in S22, The maleimidoaniline was replaced by aniline.

[0153] Comparative Example 8 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The hydroxyethyl methacrylate is replaced by methyl methacrylate; that is, the silane coupling agent in S25 is directly added to perform physical blending operation.

[0154] Comparative Example 9 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional additive II, in S25, The usage ratio of the intermediate product IV and the silane coupling agent KH171 is 1:0 according to the molar ratio of hydroxyl group to silane coupling agent; that is, the silane hydrolysis operation step is not performed.

[0155] Comparative Example 10 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The amount of the initiator AIBN used is 1.0% of the total mass of the reactants; and the reaction temperature is 70°C.

[0156] Comparative Example 11 The rest is the same as in Example 1, except that: EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, The preparation method of the functional auxiliary agent II, in S21, The amount of the initiator AIBN used is 2.0% of the total mass of the reactants; and the reaction temperature is 90°C.

[0157] The physical properties of the EPE films prepared in the embodiments of the present invention and the comparative examples were measured respectively, and the results are shown in Table 1.

[0158] Table 1 Physical test performance of each embodiment Example Transmittance / % Peel force / N ▪cm-1 Delamination after humid heat aging Wet heat aging tensile properties test UV aging yellowing index / ΔYI Example 1 92.2 187 No delamination Unstratified 1.5 Example 2 91.3 189 No delamination Unstratified 1.7 Example 3 92.6 172 No delamination Unstratified 1.6 Example 4 92.0 171 No delamination Unstratified 2.1 Example 5 92.2 186 No delamination Unstratified 1.6 Example 6 91.9 169 No delamination Unstratified 1.9 Example 7 92.2 185 No delamination Unstratified 1.7 Example 8 91.8 177 No delamination Unstratified 1.6 Example 9 92.3 173 No delamination Unstratified 1.9 Example 10 92.0 179 No delamination Unstratified 1.5 Embodiment 11 92.3 171 No delamination Unstratified 2.0 Example 12 91.9 173 No delamination Unstratified 1.6 Embodiment 13 91.6 180 No delamination Unstratified 1.5 Embodiment 14 91.8 176 No delamination Unstratified 1.5 Embodiment 15 91.6 169 No delamination Unstratified 1.5 Example 16 92.1 178 No delamination Unstratified 1.9 Comparative Example 1 92.0 94 Delamination / 3.2 Comparative Example 2 92.1 10 Delamination / 3.5 Comparative Example 3 92.3 162 Delamination / 3.0 Comparative Example 4 92.0 103 No delamination Micro-layering 2.8 Comparative Example 5 92.4 157 No delamination Micro-layering 2.2 Comparative Example 6 91.5 164 No delamination Micro-layering 2.7 Comparative Example 7 92.3 167 Delamination / 3.1 Comparative Example 8 91.9 58 No delamination Micro-layering 2.3 Comparative Example 9 92.0 16 No delamination Micro-layering 2.6 Comparative Example 10 91.4 138 No delamination Micro-layering 2.9 Comparative Example 11 92.3 151 No delamination Micro-layering 3.5 First, it can be concluded from Examples 1-16 in Table 1 that the EPE type co-extruded photovoltaic encapsulation film of the present invention has excellent light transmittance, peel strength and interlayer bonding strength; and also has a certain anti-aging effect.

[0159] It can be observed from Example 1 and Comparative Examples 1-2 that the EPE film of the present invention uses self-made functional additives I and II, which have dynamic reaction cross-linking characteristics and can effectively improve the interlayer bonding strength of the film; at the same time, functional additives I and II need to be used in combination to play the role of improving the interlayer bonding strength; It can be observed from Example 1 and Comparative Examples 3-6 that the EPE film of the present invention uses a self-made functional additive I, the furan structure is one of the bases for providing a dynamic reaction, and the silane structure has the function of enriching the functional additive at the interface; at a suitable molecular weight, a suitable degree of interface enrichment and chain entanglement with the matrix work together to improve the interlayer bonding force; It can be observed from Example 1 and Comparative Examples 7-11 that the EPE film of the present invention uses a self-made functional additive II, the maleimide structure is another basis for providing a dynamic reaction, and the silane in the molecular chain also plays a role in causing the functional additive II to migrate to the interface, and the molecular weight has a certain influence on the interlayer bonding force; In addition, the dynamic cross-linking reaction at the interface can significantly enhance the interlayer bonding strength of EPE, and also has a certain anti-aging effect, thereby improving the physical properties of the material and extending its service life.

[0160] In summary, the EPE type co-extruded photovoltaic encapsulation film of the present invention is formulated and prepared by co-extrusion using homemade functional additives I and II to improve interlayer bonding strength, which can effectively extend the service life of the product.

[0161] The test method is as follows: (1) Light transmittance: Tested in accordance with the method described in GB / T 29848-2013 “Ethylene-vinyl acetate copolymer (EVA) adhesive film for photovoltaic module encapsulation”.

[0162] (2) Peel force test: Sample preparation: 1) Prepare two pieces of adhesive film raw materials, one piece of glass and one piece of flexible backplane, all with a size of 300mm×150mm; 2) Stack the glass / film (two pieces) / flexible back sheet in sequence, put them into the vacuum laminator, and laminate them according to the temperature and time required by the product. There should be no bubbles in the film after lamination. Prepare 3 samples; 3) Cut the flexible backsheet / film layer into specimens with a width of 10 mm ± 0.5 mm at intervals of 5 mm in the width direction for testing the peeling force between the film and the glass.

[0163] Test process: According to the test method of GB / T 2790 1995, the peeling force F between the glass and the film is measured on a tensile testing machine at a tensile speed of 100mm / min ± 10mm / min.

[0164] Test results: The peel strength is calculated according to the following formula, and the arithmetic mean of 3 samples is taken, accurate to 0.1N / cm.

[0165] σ=F / B Where: σ—180° peel strength, N / cm; F—peel force, N; B—sample width, cm.

[0166] (3) Hygrothermal aging: The EPE film is subjected to a hygrothermal aging test. Conditions: Test conditions: +85°C, relative humidity 85%, test time 1000 hours. After the hygrothermal aging test, visual delamination and tensile destructive test are performed. After the tensile test is broken, observe whether there is any delamination between the layers on the cross section of the sample.

[0167] (4) UV aging: The obtained EPE film was subjected to UV irradiation aging test according to the requirements of the International Electrotechnical Commission standard IEC61345. Test conditions: the surface temperature of the test piece is 60±5℃, the UV wavelength range is 280-400nm, and the irradiation intensity is 15kW·h / m 2 , the UV irradiation test time is 2000hr.

[0168] The yellowing index (△YI) before and after the test was measured according to GB 2409.

[0169] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, characterized in that: The EPE encapsulation film includes three layers arranged in sequence, namely a first EVA layer, a POE layer, and a second EVA layer; the thickness of the first EVA layer is 50-150 μm; the thickness of the POE layer is 150-350 μm; the thickness of the second EVA layer is 50-150 μm; dynamic DA dynamic crosslinking occurs between the first EVA layer, the POE layer, and the second EVA layer.

2. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 1, characterized in that: The POE layer comprises the following raw materials in parts by weight: 100 parts of POE resin; Cross-linking agent 0.5-1.5 parts; Auxiliary crosslinking agent I 0.5-1.0 part; Functional additive I 6.0-12.0 parts; Antioxidant 0.05-0.30 parts; Light stabilizer 0.05-0.30 parts.

3. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 1 or 2, characterized in that: The first EVA layer and the second EVA layer include the following raw materials in parts by weight: EVA resin 100 parts; Cross-linking agent 0.5-1.0 part; Cross-linking agent II 0.1-0.5 part; Functional additive II 6.0-10.0 parts; Antioxidant 0.1-0.5 parts; Light stabilizer 0.1-0.5 parts.

4. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 2, characterized in that: The preparation method of the functional additive I comprises the following steps: S11, subjecting a furan dimethyl derivative containing a proton, a difunctional nucleophilic reagent, an aminosilane coupling agent and a diisocyanate to a nucleophilic addition reaction to obtain a target product, i.e., a functional additive I; The molar ratio of the proton-containing furan dimethyl derivative, the difunctional nucleophilic reagent, the aminosilane coupling agent and the diisocyanate is 0.55-0.85: 0.15-0.45: 0.10-0.20: 1.

05.

5. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 3, characterized in that: The preparation method of the functional additive II comprises the following steps: S21, subjecting epoxyolefins and hydroxyolefins to free radical polymerization to obtain an intermediate product I; The molar ratio of the epoxy olefins to the hydroxy olefins is 0.60-0.80:0.20-0.40; S22, a proton-containing phenylmaleimide is subjected to a nucleophilic addition reaction with an asymmetric diisocyanate to obtain an intermediate II; The molar ratio of the proton-containing phenylmaleimide to the asymmetric diisocyanate is 1:1; S23, reacting the intermediate II with an asymmetric diamine to obtain the intermediate III; The molar ratio of the intermediate product II to the asymmetric diamine is 1:1; S24, subjecting the intermediate product I to a ring-opening reaction with the intermediate product III to obtain an intermediate product IV; The intermediate product I and the intermediate product III are added at a molar ratio of epoxy group to amino group of 1:1; S25, hydrolyzing the intermediate product IV with a silane coupling agent to obtain a target product, i.e., a functional additive II; The usage ratio of the intermediate product IV to the silane coupling agent is 1:0.5-1.0 based on the molar ratio of hydroxyl group to silane coupling agent; and The hydroxyl group in the intermediate product IV is derived from hydroxyolefins.

6. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 4, characterized in that: The furan dimethyl derivative containing a proton is 2,5-furan dimethanol or 2,5-furan dimethylamine; and The difunctional nucleophilic reagent is a diol or a diamine.

7. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 5, characterized in that: The epoxy olefins are allyl epoxy structures or epoxy acrylate structures; The hydroxyolefin is an allyl hydroxy structure or a hydroxy acrylate structure; and The proton-containing phenylmaleimide is maleimidoaniline or 4-maleimidophenol.

8. The EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 5, characterized in that: The asymmetric diisocyanate is isophorone diisocyanate; The asymmetric diamine is isophoronediamine; and The cross-linking agent is an organic peroxide.

9. A method for preparing an EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking, characterized in that: The following steps are involved: S31, mixing, i.e. The raw materials of each layer are mixed and configured according to the formula in a mixer to obtain mixed raw materials for standby use; S32, co-extrusion, i.e. The POE layer raw materials are placed in a twin-screw extruder for melt blending; the EVA layer raw materials are placed in a twin-screw extruder for melt blending, and the materials are discharged through a co-extrusion cast film die, pulled, and stretched; S33, film formation, i.e. After thickness measurement, edge pressing, shaping, edge trimming and rolling, the EPE type co-extruded photovoltaic encapsulation film is obtained.

10. The method for preparing the EPE type co-extruded photovoltaic encapsulation film based on DA dynamic cross-linking according to claim 9, characterized in that: The POE layer extrusion process is as follows: barrel temperature 85-105°C, rotation speed 45-55rpm; and The EVA layer extrusion process is as follows: barrel temperature is 80-102° C. and rotation speed is 45-55 rpm.

11. Use of the EPE type co-extruded photovoltaic encapsulation film according to claim 1 in the preparation of solar photovoltaic modules.